Dave the plumber,
The reports I've read are complaining about premature detonation of the shell "just as it leaves the barrel". How far it got out of the barrel before it exploded isn't stated. If the loose fuse caused a catastrophic premature detonation in the barrel,
I am note sure whether they could determine if it was caused by a loose fuse, and would broadly blame it on "fuse failure".
Good morning
Dan
